Safety device for firearms

ABSTRACT

A firearm has a receiver incorporating a longitudinally reciprocatable bolt assembly which is movable between retracted or recoil and battery positions in the receiver. A trigger, including a sear, is pivotally mounted in the receiver. A hammer is pivotally mounted in the receiver in such a manner that movement of the bolt from the battery position to the recoil position urges the hammer into a cocked position. The hammer includes a first sear abutment to engage a sear on the trigger, a second sear abutment and a bolt stop sear abutment. A disconnector is pivotally mounted on the trigger pin. A compression spring is interposed between the rearward extremities of the disconnector and the trigger to urge the forward portion of the disconnector into contact with the top surface of the trigger. The disconnector includes a hook sear abutment on an intermediate portion which is adapted to engage the second sear abutment on the hammer when the trigger is in a depressed position. Should the disconnector or hook sear be removed from the firearm, the bolt stop sear abutment on the hammer is adapted to engage the bolt assembly during movement from the recoil position to the battery position for preventing the conversion of the firearm into a machine gun.

United States Patent Kennedy et a].

[451 June 20, 1972 [54] SAFETY DEVICE FOR FIREARMS [72] Inventors: Ralph C. Kennedy, Wapping; Paul A. La Violette, Haven, both of Conn; Henry M. Stromberg, Ellicott City, Md.

Colt Industries Operating Corp., New York, NY.

[22] Filed: Oct. 28, 1970 [21] Appl.N0.: 84,653

[73] Assignee:

Primary ExaminerBenjamin A. Borchelt Assistant Examiner-C. T. Jordan Attorney-Radford W. Luther [5 7] ABSTRACT A firearm has a receiver incorporating a longitudinally reciprocatable bolt assembly which is movable between retracted or recoil and battery positions in the receiver. A trigger, including a sear, is pivotally mounted in the receiver. A hammer is pivotally mounted in the receiver in such a manner that movement of the bolt from the battery position to the recoil position urges the hammer into a cocked position. The hammer includes a first sear abutment to engage a sear on the trigger, a second sear abutment and a bolt stop sear abutment. A disconnector is pivotally mounted on the trigger pin. A compression spring is interposed between the rearward extremities of the disconnector and the trigger to urge the forward portion of the disconnector into contact with the top surface of the trigger. The disconnector includes a hook sear abutment on an intermediate portion which is adapted to engage the second sear abutment on the hammer when the trigger is in a depressed position. Should the disconnector or hook sear be removed from the firearm, the bolt stop sear abutment on the hammer is adapted to engage the bolt assembly during movement from the recoil position to the battery position for preventing the conversion of the firearm into a machine gun.

7 Claims, 6 Drawing Figures P'A'TENTEDaunzo m2 3. 67 0.442

3 5 FIG.6

SAFETY DEVICE FOR FIREARMS BACKGROUND OF THE INVENTION The present invention relates to firearms, and more particularly to semiautomatic firearms. Even more particularly, the present invention relates to safety devices for semiautomatic firearms which are intended to prevent the conversion of the firearm into an automatic firearm.

Numerous semiautomatic firearms, known in the prior art, may be converted into fully automatic firearms by minor alterations and/or removal of the parts of the firing system. In many semiautomatic firearms, this conversion can be effected in a relatively short period of time. The majority of existing semiautomatic firearms can be converted into fully automatic firearms by the mere removal of the disconnector of the trigger mechanism. With many of these existing semiautomatic firearms, a skilled mechanic can effect this conversion within fifteen minutes.

SUMMARY OF THE INVENTION The present invention provides an arrangement for a semiautomatic firearm, whereby removal or alteration of the components of the trigger thereof will not render the firearm automatic. The invention provides a means which will automatically keep the firearm from being converted into a machine gun by the alteration and/or removal of existing parts. The invention is adapted for inclusion on all semiautomatic firearms in which the recoil travel of the breach mechanism or bolt assembly is used to recock the firing mechanism.

A preferred form of a trigger mechanism, according to the invention, comprises a trigger pivotally mounted in a receiver and possessing a trigger sear which cooperates with a first sear abutment on a hammer to retain the hammer in a cocked position. Upon a rearward pivotable movement of the trigger, the trigger sear is dislodged from the first sear abutment of the hammer, permitting the hammer to pivot under the bias of a hammer spring about its pivot. A bolt assembly, mounted in the receiver for longitudinal movement therein, is adapted to move the hammer to the cocked position against the bias of the hammer spring. A disconnector is pivotally mounted in the receiver intermediate the trigger and the hammer and includes a hook sear abutment thereupon which is adapted to be engaged with a second abutment on the hammer during recoil travel of the bolt assembly when the trigger in its rearward position. The hammer also includes a stop abutment thereupon which adapted, under certain conditions, to prevent the return of the bolt assembly to the battery position from the recoil position. If the disconnector or hook sear is removed from the mechanism, the stop abutment engages a surface on the bolt assembly during forward movement of the bolt assembly from its recoil position. Thus, even though the disconnector be removed, the trigger mechanism will prevent a firearm, in which it is incorporated, from firing automatically due to the engaging contact between the stop abutment and the bolt assembly during forward movement of the bolt assembly.

It is possible to incorporate the invention not only in semiautomatic firearms, but also in existing automatic cannot be readily converted into an automatic firearm.

It is another object to provide a means by which an automatic firearm may be converted into a semiautomatic firearm, wherein the conversion thereof back to its original state cannot be achieved in a facile manner.

A further object is the provision, in a semiautomatic firearm I having a trigger disconnector, hammer and bolt assembly, of a means to render the firearm inoperative should the disconnector be removed in an attempt to convert the semiautomatic firearm into an automatic firearm.

A still further object is to provide a trigger mechanism, having a trigger, disconnector with a sea: thereupon, hammer and bolt assembly, wherein the hammer is adapted to preclude forward movement of the bolt assembly into a battery position, should the disconnector be removed or the sear fail.

An even further object is the provision of a trigger mechanism, including a hammer and a bolt assembly, in which the hammer and bolt assembly are respectively provided with abutments which are adapted to contact one another during forward movement of the bolt assembly into a battery position if an attempt is made to defeat the semiautomatic functioning of the firearm.

These and other objects and advantages of the invention will become apparent from the following detailed description of an exemplary embodiment of the invention taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view of a semiautomatic firearm incorporating a trigger mechanism according to the invention.

FIG. 2 is a fragmentary vertical sectional view of the receiver portion of the semiautomatic firearm of FIG. 1, in which the hammer is rotating towards the firing pin.

FIG. 3 is a fragmentary vertical sectional view showing the hammer in firing position.

FIG. 4 is a fragmentary vertical sectional view showing the components of the trigger mechanism when the bolt assembly has returned the hammer to a cocked position and the trigger is depressed.

FIG. 5 is a fragmentary vertical sectional view showing the components of the trigger mechanism after the trigger has been released from the depressed position of FIG. 4.

FIG. 6 is a fragmentary vertical sectional view illustratingthe engagement between the bolt assembly and the hammer occasioned during the movement of the bolt assembly from the recoil to the battery position when the hook sear of the disconnector is removed in an attempt to make the firearm automatic.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings in greater detail, wherein like reference characters indicate like parts throughout the several figures, there is shown in FIG. 1 a firearm 10, which is a semiautomatic firearm. The firearm 10 includes a stock 12 mounted on a receiver 14, the receiver having a cartridge. magazine 16 mounted therein. A barrel 18 is operatively connected to the receiver and has a hand grip 20 mounted thereupon for isolating the hand of a shooter from direct contact with the barrel. As shown in FIG. 2, the receiver 14 embodies a trigger mechanism, generally indicated at 22, and a bolt assembly, generally indicated at 24. The receiver 14 is composed of a lower receiver 26, housing the lockwork of the rifle, and an interconnected upper receiver 28, which is provided with a longitudinal cavity or chamber 30, in which is mounted the bolt assembly 24 for reciprocating movement therein. The bolt assembly 24 includes an elongated bolt carrier 32 which is of the type shown and described in US. Pat. No. 2,951,424. A gas chamber 34 is defined by the carrier 32 and has a bolt 36 mounted therein for movement relative to the bolt carrier.

The bolt 36 envelops a firing pin 38 extending axially therethrough. The firing pin 38 is adapted to engage and fire a cartridge when the bolt assembly is in battery position, that is, locked in the forward extremity of the receiver 14, as illustrated in FIG. 2.

A recoil device 40 (partially shown) is housed in a receiver extension 42 which is threadably secured to the receiver 14. A

gas port (not shown), which is connected to the barrel 18 forward of the tenninus of the firing pin 38, serves to actuate the automatic recoil which causes ejection of a spent cartridge shell and subsequent successive chambering of cartridges 44 located in the magazine 16. Upon firing the firearm illustrated in FIG. 1, the bullet passes outwardly through the barrel 18 under the impetus of the expanding powder gases. The portion of these gases which reaches the aforementioned gas port passes therethrough and into a gas passage tube (not shown) connecting the gas port with a mating port 46 located within a bolt carrier key 48. The mating port 46 communicates with an annular chamber 50 which forms a part of the gas chamber 34. As more fully set forth in the abovementioned U.S. Pat. No. 2,951,424, chamber 50 fills with high pressure exhaust gas which drives the bolt carrier 32 rearwardly within cavity 30 and initially causes an annular shoulder 52 of the carrier 32 to engage the flange 54 of the firing pin 38.

For purposes of describing the instant invention, it will suffice to note that these gases will impart a rearward momentum to the bolt assembly which is absorbed by the compression of the recoil device 40 until the bolt assembly has reached its recoil or retracted position. Upon dissipation of the rearward momentum of the bolt assembly 24, the recoil device returns the bolt assembly to the locked battery position illustrated in FIG. 2. During the recoiling operation, the expended cartridge shell is, of course, ejected and a new cartridge is fed from the magazine 16 into the firing chamber (not shown).

The trigger mechanism 22 is somewhat similar in design and operation to that mechanism described in U.S. Pat. No. 3,045,555, but, of course, it is designed to furnish only semiautomatic operation of the firearm 10. The trigger mechanism 22 comprises a trigger 56 which is pivotally mounted within the lower receiver section 26 by transversely oriented pivot pin 58. Trigger 56 has an elongated upper portion which includes a forward trigger sear 60 adapted, in a manner hereinafter described, to retain a hammer 62. Additionally mounted on the pivot pin 58 is a disconnector 64, the lower portion of which is located within a groove 66 in the upper portion of the trigger 56. A compression spring 68 is interposed between the bottom of the groove 66 and the under side of the disconnector 64 in order to urge the disconnector in a clockwise direction about pivot pin 58.

The hammer 62 is provided with a first sear abutment 70 in the forward portion thereof and a second sear abutment 72 in the intermediate portion thereof. The hammer 62 is also provided with a bolt stop abutment 74 in the upper portion thereof which is adapted to engage the bolt assembly 24 in a manner hereinafter described.

The disconnector 64 includes a vertically extending portion which incorporates a hook sear abutment 76. The trigger 56, by virtue of its pivotal mounting on pin 58, is adapted to pivot from a first position, in which the sear 60 thereof engages the first sear abutment 70 of the hammer 62, to a second position angularly spaced in a clockwise manner from the first position, in which the hook sear abutment 76 on the disconnector 64 engages the second abutment 72 of the hammer 62. The hammer 62 is maintained in a cocked non-firing position by the cooperative interengagement between either the trigger sear 60 and the first sear abutment 70 or the hook sear abutment and the second sear abutment, the interengagements being respectively maintained by the bias of a trigger spring 78 and the pressure of the shooters finger.

Upon rearward pivotal movement of the trigger 56 about its pivot pin 58 against the bias of the trigger spring 78, the hammer swings upwardly under the bias of a hammer spring 79 about its mounting pivot 80. During upward swinging between a cocked position and a firing position, in which it abuts the firing pin 38, the hammer passes through a bottom longitudinal aperture 82 formed in the bolt assembly carrier 32. Upon striking the firing pin 38, a chambered cartridge is fired from the barrel 18. When the bolt assembly 24 recoils under the influence of the expanding gases in the barrel, the hammer 62 is urged by the carrier 32 in a downward or counterclockwise direction. Assuming that the trigger 56 is retained in its depressed or second position during this downward movement of the hammer 62, the second sear abutment 72 of the hammer 62 will engage the hook sear abutment 76 of the disconnector 64 after slightly displacing the disconnector in a counterclockwise direction about the pivot 58. Conversely, if the trigger 56 is immediately returned to its first position after the firing of the chambered cartridge, the hammer 62 will be retained in its cocked position by the engagement of the trigger sear 60 and the first sear abutment 70. Normally, the trigger will be momentarily retained in its second position after the firearm has been fired, and thus the recoil of the bolt assembly 24 normally causes the second sear abutment 72 to engage hook sear abutment 76. When the trigger is released after this engagement has been effected, the trigger sear 60 will move into engagement with the first sear abutment 70 after the second sear abutment 72 and the hook sear abutment 76 move out of engagement. After this occurs, the mechanism is poised to fire another cartridge.

The carrier 32 of the instant invention differs slightly from those described in the aforementioned patents in that a portion thereof has been removed to permit the bolt stop abutment 74 to contact the rearmost flange 84 of the firing pin 38, if the second sear abutment 72 and the hook sear abutment 76 fail to engage one another due to the removal, alteration or breakage of abutment 76 or abutment 72, or the complete removal of the disconnector 64 from the mechanism, it can be seen, in FIG. 2, that the elongated aperture 82 extends to flange 54 of firing pin 38, and thereby permits the stop abutment 74 to engage the flange 84 on its right side or forward surface.

The various configurations, which the trigger mechanism may assume, are shown in FIGS. 3 through 6. Referring to FIG. 3, the hammer is shown in its firing position after it has struck the firing pin 38 and fired a chambered cartridge from the barrel 18. It will be noted that in this position of the hammer, an operator of the firearm will normally maintain the trigger 56 in its second position which is therein illustrated.

Turning now to FIG. 4, it will be noted that the hammer 62 has been urged into engaging contact with the disconnector 64 by the recoil of the bolt assembly 24, the trigger 56 being retained in its second or depressed position. In this configuration, the hammer 62 is prevented from swinging upwardly to strike the firing pin by the contact between the second sear abutment 72 and the hook sear abutment 76. It should be readily apparent that if the trigger mechanism were modified so that the abutrnents could not engage one another, the hammer 62 would again strike the firing pin 38 upon forward movement of the bolt assembly were it not for the exposed flange 84.

When the trigger 56 is released from its second position, illustrated in FIG. 4, the abutments 72 and 76 move out of engagement by virtue of the pivoting of trigger 56 under the bias of trigger spring 78; and the trigger sear 60 and the first sear abutment 70 of the hammer 62 move into engaging contact to retain the hammer in a cocked configuration, as shown in FIG. 5. It will be noted that, with reference to FIG. 5, the trigger 56 is in its first position. In this configuration, depression of the trigger 56 results in disengagement between the trigger sear 60 and the first sear abutment 70, thereby permitting the hammer 62 to swing upwardly in a clockwise fashion and strike the firing pin 38.

FIG. 6 shows the trigger mechanism of FIGS. 2-5, wherein the hook sear abutment 76 of the disconnector 64 has been completely removed in an attempt to convert the semiautomatic firearm into an automatic firearm or machine gun. As FIG. 6 shows, this modification will not defeat the semiautomatic nature of the firearm, as the bolt stop abutment 74 will engage the forward side of the rearward flange 84, thereby preventing completion of the movement of the bolt assemblyfrom the recoil position to the battery position. It will be understood that it is within the scope of the invention to form a mating abutment on the lower portion of the carrier to engage a stop abutment on the hammer.

As will be appreciated from the foregoing, existing automatic firearms, such as those shown in the aforementioned U.S. Patents, or any other semiautomatic or automatic firearm which utilizes the movement of a breach or bolt assembly to cock the hammer, may be readily modified in accordance with the invention. To modify an automatic firearm to attain a structure in accordance with the invention, it is merely necessary to remove the automatic sear, provide a suitable abutment or abutments on the bolt assembly, and, if necessary, an abutment on the hammer to engage the one on the bolt assembly. The invention thus provides an economical means for changing an automatic firearm to a semiautomatic firearm which cannot easily be converted into an automatic firearm. A salutary feature of the above-described invention is the fact that it not only prevents conversion of a firearm, into which it is incorporated, into an automatic firearm, but also does not adversely effect the semiautomatic operation of the firearm.

As will be apparent to those skilled in the art, further modifications and adaptations of the above-described structure are possible without departure from the spirit and scope of the invention as defined in the appended claims.

What we claim is:

1. In a trigger mechanism, the combination comprising:

a receiver;

a bolt assembly mounted for longitudinal movement in the receiver between recoil and battery positions;

a hammer pivotally mounted in the receiver such that movement of the bolt from the battery position to the recoil position urges the hammer into a cocked position; and

means to prevent movement of the bolt assembly from the recoil position to the battery position when the hammer is not retained in the cocked position.

2. The combination, as defined in claim 1, wherein the movement preventing means comprises:

a stop abutment on the hammer; and

a surface on the bolt assembly, the surface being engageable by the stop abutment during movement of the bolt assembly from the recoil position to the battery position.

3. The combination, as defined in claim 1, further including:

a trigger having a sear thereupon pivotally mounted in the receiver;

a disconnector having a hook sear abutment thereupon operatively connected to the trigger;

a first sear abutment on the hammer for engagement by the sear abutment on the trigger to retain the hammer in the cocked position; and

a second sear abutment on the hammer for engagement by the hook sear abutment when the trigger is depressed to retain the hammer in the cocked position.

4. In a trigger mechanism, the combination comprising:

a receiver;

a bolt assembly mounted for longitudinal movement in the receiver between recoil and battery positions;

a hammer pivotally mounted in the receiver such that movement of the bolt from the battery position to the recoil position urges the hammer into a cocked position; and

surface means on the bolt assembly to engage the hammer during movement of the bolt assembly from the recoil to the battery position when the hammer is not retained in the cocked position.

5. The combination, as defined in claim 4, further including:

a trigger, having a sear thereupon, mounted in the receiver;

a disconnector, having a hook sear abutment thereupon,

operatively connected to the trigger;

a first sear abutment on the hammer for engagement by the sear on the trigger to retain the hammer in the cocked position; and

a second sear abutment on the hammer for engagement by the hook sear abutment when the trigger is depressed to retain the hammer in the cocked position.

6. In a trigger mechanism, the combination comprising:

a receiver;

a bolt assembly mounted in the receiver for longitudinal movement therein between recoil and battery positions; a hammer pivotally mounted in the receiver such that movement of the bolt from the battery position to the recoil position urges the hammer into a cocked position; and

means on the hammer to engage the bolt assembly to prevent movement thereof from the recoil position to the battery position.

7. in a trigger mechanism, the combination comprising:

a receiver;

a bolt assembly mounted for longitudinal movement in the receiver between recoil and battery positions;

a trigger, having a sear thereupon, pivotally mounted in the receiver for movement between a first position and a second position;

a hammer pivotally mounted in the receiver such that movement of the bolt from the battery position to the recoil position urges the hammer into a cocked position;

a first sear abutment on the hammer to engage the sear on the trigger when the hammer is in the cocked position and the trigger is in the first position;

a second sear abutment on the hammer;

a rotatable disconnector, having a hook sear thereupon, operatively connected to the trigger, the hook sear being engageable with the second sear abutment on the hammer to retain the hammer in the cocked position when the trigger is in the second position; and

a stop abutment on the hammer to engage the bolt assembly to prevent movement of the bolt assembly from the retracted position to the battery position if the hook sear or disconnector is removed from the mechanism. 

1. In a trigger mechanism, the combination comprising: a receiver; a bolt assembly mounted for longitudinal movement in the receiver between recoil and battery positions; a hammer pivotally mounted in the receiver such that movement of the bolt from the battery position to the recoil position urges the hammer into a cocked position; and means to prevent movement of the bolt asSembly from the recoil position to the battery position when the hammer is not retained in the cocked position.
 2. The combination, as defined in claim 1, wherein the movement preventing means comprises: a stop abutment on the hammer; and a surface on the bolt assembly, the surface being engageable by the stop abutment during movement of the bolt assembly from the recoil position to the battery position.
 3. The combination, as defined in claim 1, further including: a trigger having a sear thereupon pivotally mounted in the receiver; a disconnector having a hook sear abutment thereupon operatively connected to the trigger; a first sear abutment on the hammer for engagement by the sear abutment on the trigger to retain the hammer in the cocked position; and a second sear abutment on the hammer for engagement by the hook sear abutment when the trigger is depressed to retain the hammer in the cocked position.
 4. In a trigger mechanism, the combination comprising: a receiver; a bolt assembly mounted for longitudinal movement in the receiver between recoil and battery positions; a hammer pivotally mounted in the receiver such that movement of the bolt from the battery position to the recoil position urges the hammer into a cocked position; and surface means on the bolt assembly to engage the hammer during movement of the bolt assembly from the recoil to the battery position when the hammer is not retained in the cocked position.
 5. The combination, as defined in claim 4, further including: a trigger, having a sear thereupon, mounted in the receiver; a disconnector, having a hook sear abutment thereupon, operatively connected to the trigger; a first sear abutment on the hammer for engagement by the sear on the trigger to retain the hammer in the cocked position; and a second sear abutment on the hammer for engagement by the hook sear abutment when the trigger is depressed to retain the hammer in the cocked position.
 6. In a trigger mechanism, the combination comprising: a receiver; a bolt assembly mounted in the receiver for longitudinal movement therein between recoil and battery positions; a hammer pivotally mounted in the receiver such that movement of the bolt from the battery position to the recoil position urges the hammer into a cocked position; and means on the hammer to engage the bolt assembly to prevent movement thereof from the recoil position to the battery position.
 7. In a trigger mechanism, the combination comprising: a receiver; a bolt assembly mounted for longitudinal movement in the receiver between recoil and battery positions; a trigger, having a sear thereupon, pivotally mounted in the receiver for movement between a first position and a second position; a hammer pivotally mounted in the receiver such that movement of the bolt from the battery position to the recoil position urges the hammer into a cocked position; a first sear abutment on the hammer to engage the sear on the trigger when the hammer is in the cocked position and the trigger is in the first position; a second sear abutment on the hammer; a rotatable disconnector, having a hook sear thereupon, operatively connected to the trigger, the hook sear being engageable with the second sear abutment on the hammer to retain the hammer in the cocked position when the trigger is in the second position; and a stop abutment on the hammer to engage the bolt assembly to prevent movement of the bolt assembly from the retracted position to the battery position if the hook sear or disconnector is removed from the mechanism. 